1. Field of the Invention
This invention relates generally to sporting equipment and more particularly to an interocclusal sports prophylaxis which protects both the upper and lower dentitions, as well as the temporomandibular joint, against impact.
2. Antecedents of the Invention
The earliest mouthguards were introduced in the 1920's for use in boxing and were formed of pieces of rubber cut to the shape of the maxillary arch and held in place by clenching the teeth together. It was difficult, if not impossible to achieve oral airflow because the teeth were required to be clenched together to maintain the mouthguard in position. Oral airflow was crucial, however, as increased levels of oxygen intake were required during physical exertion.
Additionally, early mouthguards were loose fitting and easily displaced upon impact. There was a significant risk of dislodgement and airway obstruction, which was particularly hazardous with reference to boxing, where there was a likelihood of a participant being rendered unconscious.
Improvements over the early rubber mouthguards included a design illustrated in U.S. Pat. No. 2,521,039, issued to Cartheter, which disclosed a rubber mouthguard having a central air passageway. Unfortunately, such mouthguard, too, was kept in place only by clenching and interfered with speech.
Attempts at improving rubber mouthguards lead to the employment of materials capable of conforming to tooth surfaces, including self fitted mouthguards which were immersed in boiling water and then formed in the mouth by biting. Problems encountered with such mouthguards included difficulty in centering the dentition during the self-fitting procedure.
In U.S. Pat. No. 5,566,684, issued to Wagner and assigned to the assignee of the present invention, there is disclosed a molded mouthguard having a thermoplastic channel shaped trough which carried a low softening temperature thermoplastic fill. After heating in boiling water, the mouthguard was inserted into the mouth and the fill conformed to the impression of the upper teeth when biting pressure was applied. Lacking, however, was positive engagement with the mandibular dentition.
In U.S. Pat. No. 5,406,963 issued to Adell, there was provided a mouthguard including a moldable liner which extended into both the upper end lower occlusal surfaces, however, such mouthguard lack the ability to adequately protect the lower dentition against shocks and further inhibited oral breathing, since there was intimate contact of both upper and lower occlusal surfaces with the liner material within which the occlusal surfaces were imbedded.